A wise man sought to find the true nature of reality. He meditated daily in front of the fence surrounding his humble dwelling. He would look out at the world through a missing slat in the fence. Beyond his yard was a green pasture with a small herd of cattle. Every morning the cows would walk past the fence in single file on their way to graze. Every evening they would return, again in single file. As each beast passed by the wise man, he would first glimpse the snout through the missing slat, followed by the head, body and finally the tail.
One morning after the herd had passed him, the wise man sat in deep contemplation. Suddenly, as he was struck by total infinite understanding - he arose and proclaimed, "The nose causes the tail!".
Thanks to Neal Raj